This book makes a serious effort at bringing forth and synergistically combining the concepts of green chemistry, sustainability and nanotechnology and should motivate scientistsat all levels to think clearly and seriously about creating and optimizing novel and sustainable green approaches to nanotechnology. The chapters in this book can be divided into three broad categories: 1) Advancement in research on pollution control through the green chemistry principles of nanotechnology; 2) Emergence of nanomaterials in widespread applications in various scientific fields, including but not limited to sensors and catalysts; 3) Extension of research into nanotechnology and green nanotechnology at a rapid pace. Review articles on the individual aspects of these diverse and complementary topics have become important resources for researchers, industry leaders, and regulators, both nationally and internationally. This book contains a few chapters associated with these particular themes, and provides glimpses of the many difficulties and challenges faced by those who seek to not only understand but also regulate the new nanomaterials. Nanotechnology represents a unique field of science, and necessitates new and novel sustainable approaches to create usable end products for the market place with the primary goal of yielding less adverse effects upon both human health and the environment.